I'm having trouble with this question..

a savings account is started with an initial deposit of $500. the account earns 1.5% interest compounded annually.

(a) write an equation to represent the amount of money in the account as a function of time in years.

(b) find the amount of time it takes for the account balance to reach $800. show your work.

A) Total = Principal * (1 + rate)^years
Total = 500 * (1.015)^years

b) The equation has to be solved for years.
http://www.1728.org/compint2.htm
Years = {log(total) -log(Principal)} ÷ log(1 + rate)
Years = [log (800) - log(500)] / log (1.015)
Years = (2.903089987 -2.6989700043) / 0.0064660422492
Years = 0.2041199827 /  0.0064660422492
Years = 31.567993965